Air-supply system for two-stroke-cycle engines



7 Feb. 28, 1928. I 1,660,942

H. W. SUMNER AIR SUPPLY SYSTEM FOR TWO-STROKE CYCLE ENGINES Filed Sept. 17, 1925 3 Sheets-Sheet 1 INVENTO".

Henry Wfi'umner AT ORNEYS Feb. 28, 1928.

H. w. SUMNER AIR SUPPLY SYSTE FOR TWO-STROKE CYCLE BIGINES Filed Sept. 17. 1925 3 Sheets-Sheet 2 INVENTOR I Henri. 'WSumner Feb. 28, 1928.

H. W. SUMNER AIR SUPPLY SYSTEM FOR TWO-STROKE CYCLE ENGINES Filed Sept. 17, 1925 3 Sheets-Sheet 3 INVENTOR 4 ATTO EY was Fa. 28,1928.

PATENT oFFlcs.

HENRY W. SUMNER, OF SEATTLE, WASHINGTON.

am su'rrmr SYSTEM ron rwosrnox'nbrcnn enemas.

Application filed September 17, 1925. Serial No. 56,866.

My invention relates to means employed for supplying air to internal combustion engines of the two-stroke cycle type, and also to the provision of space for containl ing the air compressed by the scavenging pump of such engines.

. the rame of the engine as to provide therein suitable channels and storage spaces for the air which is compressed by the scaveng ng .or air supply pump, whereby the rovislon of special containers outside of t e frame may be avoided.

The drawings herewith illustrate the man- 1 nor in which I have secured these results, the particular construction being illustrative of the principles employed.

Figure 1 is a transverse elevation of an engine having my invention embodied therein.

Figure 2 is a side elevation, the same being partly in section, the section parts being approximately on the line indicated by the broken line 2-2 of Figure 1. Figure 3 is a diagrammatic pers ctive of certain elements of the frame, il u'strating the location and the manner of connecting the spaces in said frame in order to provide the air storage channels in which the compressed air delivered from the pump is stored until admitted to the cylinder. I

Figure 4 shows in perspective a plate which is' used as avalve for controlling the admission of air to the pump. The type of engine with which my invention is intended'to be used is the two-stroke cycle internalcombustion engine. As herein illustrated this has a frame of the accepted marine type, that is, with inclined osts forming an inverted U. The particuar construction of the iston, its cylinder, and the arts of the englne other than those spec-ifieal described, ma be anything which is fhund to'suitably t with the parts 45 which are the specific'feature's of my inven: tion. The piston 1 is of the inverted skirt type. lhe cylinder 2 .has an admission port 20 and an exhaust rt 21. These are covered 60 and uncovered rtion of the cylinder casting" is enl'ar I and so connected with invention consists in so constructing ythe upper edge of the piston after an accepted type of-constru'c- "tion. The lower the main frame as to form a chamber 22 which connects with the supply port 20 and with the lower open end of the cylinder 21 This chamber 22 also forms a cross connection between the two. posts 3 and 30 of a pan.

The posts 3 and 30 are hollow and are used both as connecting passages between the air inlet valve and the pump, and as portions of the air storage space into which the air -is compressed by the pump and held for a moment before being admitted to the power cylinder.

One of the posts of the frame, as the post 3, has an opening controlled' by a valve 4. Connecting with this valve and exterior thereof is a hollow casting 40 which connects with a header 41, the latter extending lengthwise of the engine and connecting with all of the varlous cylinders for the purpose of supplying air thereto.

At one end of the header. an upward extension 42 is provided in which is mounted a damper or valve 43 by which the effective area; of the opening may be controlled.

In carrying out my invention two power cylinders with their associated parts, including their separate frames, are linked together to form a single power unit. The engine may, however, be made up of two or more such power units. Each half of each unit is essentially a duplicate of the other half, the difference being this, that a single air compression pump is supplied for each two cylinder units, and the exact position and location of the spaces employed for the air storage reservoir varies slightly as between the two halves of the unit.

At or near the base of the post 30 which is at the opposite side of the engine from that which carries the air inlet valve, is concylinder 5 has a piston 50 therein and, a rod 51 extending upwardly therefrom. This pump is double-acting. It is operated through a rock arm 6 mounted upon a pivot or fulcrum shaft 60 and at its other end connected with the cross head 62 by a short link 61. A similar short link 63 is employed for connecting the opposite end to the rod '51 of the air pump. 1

It will be notedthat near the. lower end of the post 30- of the engine frame is pro- 1 be obtained in part at least vided a partition or web 31' extending across the same. The upper end of "the air pump connects with the upper portion of the chamber in the post 30 by a port 52, while the lower end of the air pump cylinder conneets with the ortion of said post below the partition 31 y a port 53.

That post at the front side of the engine which is opposite the one to which the air pump is directly connected communicates at its lower end with a passage-or chamber 32 formed in a portion of the bed frame which extends parallel with the axis of the engine shaft. The portion at the bottom of the post 30 to which the lower end of the air pump connects is also connected with a.

corresponding chamber 33- formed in the engine base at the opposite side, that is, at the rear side of the engine. The other end of this chamber 33 connects with the other rear post 30 of the engine which is the com panion in the engine unit. This latter post 30 connects with the corresponding chamber 32 at the. lower end of the power cylinder and with the post 3 which is a part of the same frame.

It is the purpose to have these chambers of such volume that they may serve as channels for the supply of air to the scavenging pump and also as storage cham bers for the air compressed by the pump and also by the power piston in its downward movement. In order to balance the storage capacity into which opposite ends of the air pump discharge, I may provide intercepting or cut-oil" partitions or diaphragms as 55 which ma be positioned at such point in the length 0 the post in which it is placed as to make the two storage chambers of equal volume. The same result may by varying the position of the diaphragm 31.

In Figure 3 has been shown a diagrammatic perspective of the engine post and frame for an engine unit. The portions thereof which are used as the air passages and storage chambers are indicated by the dash-aild-dot lines employed. The single dash-anddot line indicates that ortion which is employed in connection with the lower end of the air cylinder, while the double dash-and-dot line indicates the portion employed in connection with the upper end of the air cylinder. By properly proportioning these chambers and with this properly locating the cut-ofl' partitions, as 55 and 31, the capacity of the chambers emdployed may be balanced for the two cylin ers of a power unit. It is evident, of course, that other means for equalizing the capacity of these chambers and also for in creasing or decreasing them may be employed. By the above expedient the frame itself is used as the storage chamber for the compressed air and therefore the space which would be taken by a separate air storage tank is available for other purposes.

What I claim as my invention is:

1. An internal combustion engine of the two-stroke cycle type having its engine units grouped in pairs, and an air pump for each pair, the frame .and base having channels forming two air storage chambers communicating each with its respective cylinder and end of the air pump.

2. A two-stroke cycle internal combustion engine having its power cylinders, pistons and frames arranged in pairs, a double acting scavenging pump for each pair of engine cylinders, and operating connections for said pump from the power pistons, the frame posts and base members connecting posts of each pair of the engines being hollow and communicating to serve as communicating passages and pressure storing chambers for the engine operating air, diaphragms divid end of the scavenging pump discharging into the frame posts of one of its engines, and the other end into the frame posts of the other of its engines. 4 i

3. An internal combustion engine 'of the two-stroke cycle type composed of two cylinder units placed side by side, each cylinder having its own A-frame, piston and connected parts and a base common to both cylinder frames, each frame having a chamber enclosing the lower part of its cylinder, and hollow posts connecting with said cylinder enclosing chamber, the base having a hollow girder member at each side extendin between the bases of. the posts for-both framesfsaid base girders at one. sideof the engine communicating only with the hollow post of one cylinder and at the other side with the hollow post of the other cylinder, as an air inlet valve upon .eaeh of the posts at one side of the engine, an air scavenging longitudinal base chamber communicating with the posts of the other A-frame.

4. An engine frame for'internal combusq tion engines of the type employing an air pump to supply air under pressures above atmospheric, comprising an air pump, as

A-frame for eachcylinder, said frame having hollow posts forming the sides of the A- frame and serving as receivers for the compressed air, said passages having controlled communication at different times with the engine cylinder and with the pu and a base for said A-frames having a lm ilow longitudinal member at each side, the base pasv sages thus for-med atone side of the base communicatlng with the air pump to receive the discharge from one side of said pum and with a 0st of one A-frame and at t e 5 other side '0 the base connecting the posts of' both A-frames, I A

5. An engine frame for internal combusmploying an air tion engines of the type supply under pressure, comprising an A- frame for eachcylinder and said A-frames being 'holairs, the posts of ow and for each frame communicating at 7 their upper ends with each Othenandv with their respective cylinders, the diagonally op- 15 posite posts of each pair of A-inames having phragm adapted for 'a transverse-diaphragm forming two sepa rate chambers therein, and a base'frame hava hollow longitudinal beam at each si e forming communicating, passages -be-- tween the bases of the posts (if the pairs'ati 

